Medicinal products can be harmful if taken in excess amount or by someone other than the intended recipient, especially small children. Accordingly it is customary to provide packages for certain products which cannot readily be opened by children but which nevertheless contain features allowing an adult to open the package once it is manipulated in a special way. This invention relates to a three seal sachet, commonly also known as a stick pack, which has a longitudinal seal and two transverse seals. Such three seal sachets are frequently used for food items but do not typically come with child resistant features. A tear notch may be provided in such sachets but it is usually located in an obvious position at the edge of the sachet such that the method of opening is either obvious or the package can be opened inadvertently.
PCT application WO 95/01921 describes a stick pack for liquid drugs, but it too provides a notch on the edge of the pack which provides insufficient challenge to opening by a young child.
U.S. Pat. Nos. 5,222,813 and 5,371,997 describe packaging bags with a longitudinal fin seal and tear-open slits which extend through the fin seal but, like WO 95/01921, only disclose a notch starting on the edge of the pack and therefore with insufficient child resistance.
U.S. Pat. Nos. 5,511,665 and 5,472,093 concern packages suitable for pharmaceuticals incorporating ‘hidden notches’ which only reveal a tear slit after a particular fold is made, thus making the method of opening much more difficult for a small child to discern but nevertheless allowing opening by an adult able to follow instructions.
It is an object of the present invention to improve the child resistance of stick or three seal packs or sachets which have advantages in the dispensing of liquids and powders. It is a further object of the present invention to provide three seal packs or sachets which have improved resistance to flavour loss and thus to make them more suitable for medicinal products where it is important to have a flavour to mask the bitter taste of many medicinal active agents.
These and other objectives will become readily apparent from the detailed description that follows.